Medicine tablets and capsules are typically packaged in vials or small bottles having a closure which is resistant to removal by a child. In this way, the medicine is readily available for administration to the patient, but cannot easily be accessed by children. These child resistant closures are mandated by law in the United States and many other countries for medicine which could be poisonous to children.
Child resistant closures can be grouped into two categories. One category of child resistant closures includes closures that require the simultaneous application of a force urging the closure toward the container and a rotative force, which are sometimes called "push and turn" closures. A force urging the closure toward the container engages a set of tabs on one part of the closure with a set of notches on another part of the closure, so that a rotative force applied to the first part of the closure is translated into a rotative force on the second part of a closure in order to unthread the second part of the closure from the threaded neck of the bottle. In another embodiment of the push and turn type child resistant closures, the neck of the container holds a set of bayonet lugs which mate with a mating set of bayonet lugs on the inside of an axial skirt of the closure. A force urging the closure toward the container is necessary to disengage the bayonet lugs from the mating lugs, and then a rotative force is necessary to position the mating lugs in the spaces between the bayonet lugs to allow removal of the closure.
The second category of child resistant closures employ a radially outward protruding bead on the neck of the container and one or more radially inward protruding mating beads on the axial skirt of the closure. The bead on the closure snaps over the bead on the neck of the container. The bead on the neck of the container is interrupted, such that there is no bead on a short circumferential portion of the neck. The axial skirt of the closure includes a radially inward extending protrusion having a circumferential length that allows it to pass through the interruption in the bead of the container neck. Therefore, the closure can be removed from the container only when the closure and container are angularly aligned such that the closure protrusion matches the container neck bead interruption so that the closure bead can be snapped off from the container neck bead. If there is no such alignment, the closure protrusion is retained beneath the container neck bead and so the closure cannot be removed. The container neck bead is typically tapered on the upper side, so that the closure protrusion will snap over the container neck bead to replace the closure on to the container even without aligning the closure protrusion with the container neck bead interruption.
Finally, there is normal]y a symbol on the outer surface of the closure and on the outer surface of the container neck to indicate the location of the closure protrusion and container neck bead interruption, respectively, so that the user can ascertain the alignment of those elements. The marker on the closure is usually a protruding arrow to assist the user in applying a force urging the closure away from the container once the proper alignment is achieved to accomplish removal of the closure from the container. Even when the markers are lined up so that the closure protrusion aligns with the container neck bead interruption, it is still necessary to apply a fairly significant force urging the closure away from the container to snap the closure bead past the container bead to open the container. It is this second category of child resistant closures--the so-called line-up-thearrows type--with which the present invention is primarily concerned.
A drawback to these line-up-the-arrow type child resistant closures is that it not only resists opening by a child but also resists opening by an adult. The significant force urging the closure away from the container once the arrows are lined up is very difficult for a person with a muscular or joint disorder or injury, such as arthritis, or for people who are elderly or infirm. Such persons may suffer pain when applying that force, or may be simply unable to apply the requisite force at all regardless of how much pain they are willing to suffer. The result is that either the medicine does not get taken, the patient must obtain help in taking the medicine, or the patient simply defeats the child resistant aspects of the closure by keeping the closure unfastened from the container.
There are several devices in the prior art to assist in the removal of line-up-the-arrow closures from a container. For example, U.S. Pat. No. 4,770,069 by Mikan, et al. discloses an opener having a plate with a projecting ring slightly larger than the cap. The ring has an opening to receive the projecting marker on the cap. The plate acts as a lever so that applying a force urging the plate toward the container at the plate edge opposite the opening in the ring pries the cap away from the closure. A significant limitation to the device of Mikan is that it is limited to use with a single cap size. Also directed toward the removal of child resistant closures from medicine vials and the like is U.S. Pat. No. 3,885,478 by Evans. The Evans device is somewhat limited in that it grasps one side of the closure but not the other side of the closure, and so the grasping end of the device tends to slip away from the center of the closure and off the closure end that is grasped.
The prior art includes other devices designed less specifically toward the removal of child resistant closures and more generally toward the removal of ordinary bottle caps. Such devices include devices disclosed in U.S. Pat. No. 4,433,597 by Rowland, 4,455,894 by Roberts, 4,178,646, two by Swartz, et al., 4,514,565 by Capriccio, 2,440,485 by Ranseen, and 2,568,612 by Cullen.